An apparatus has conventionally been proposed which determines whether or not a driver has fallen into an abnormal state where the driver loses an ability to drive a vehicle (for example, a drowsy driving state, a mental and physical failure state, and the like), and decelerates the vehicle when the driver is determined to be in such an abnormal state (for example, refer to Japanese Patent Application Laid-Open (kokai) No. 2009-73462.).
It should be noted that hereinafter an “abnormal state where a driver loses an ability to drive a vehicle” is simply also referred to as an “abnormal state”. Besides, a vehicle which a driver who is in the abnormal state is in is also referred to as an “own vehicle”.